This invention relates generally to pipe plugs and more specifically to temporary pipe plugs as used during the construction of sewer lines and the like.
In the course of construction of sewer or water lines, it is often desirable to plug the open end of a pipe in a temporary or semi-temporary manner. The simplest means for effecting a sort of plugging is to prop a piece of plywood of suitable size against the open end of the pipe and to hold it in place by driving a stake behind it. This method, although widely used, does not afford a good seal and allows gravel and other debris to enter the pipe.
Other more sophisticated devices are available but each has certain drawbacks when compared with the present invention. None of these are known to be available in sizes larger than 12 inches in diameter.
A plug is available in which an expandable mass of rubber is squeezed between two metal plates by means of a threaded member, the latter of which extends beyond the end of the pipe. This plug is awkward to install and with the threaded portion exposed, the plug may be dislodged or broken if the threaded member is struck by a tool during the course of construction.
Air bags have also been used to temporarily seal the ends of pipes, but they are subject to puncture and require an air line to install them.
Other Plugs, such as ductile iron plugs, may be used in a temporary manner to seal a pipe. However, these plugs are very heavy and must be pushed into place with a backhoe. They are very difficult to remove.
The present invention overcomes the problems associated with the above-mentioned plugs. The present invention provides a lightweight, durable and inexpensive temporary pipe plug. The plug of this invention may be installed and removed manually. When in place, the plug is virtually flush with the end of the pipe it seals and, therefore, not subject to damage by tools or machinery being used in its vicinity.
It is one object of the present invention to provide a temporary pipe plug that may be installed and removed manually.
Another object of the present invention is to provide a pipe seal that is not susceptible to damage from the use of tools and machinery in its vicinity.
Yet another object of the invention is to provide a temporary pipe plug that may be conveniently made in virtually any size.
In accordance with the invention, a temporary plug for placement into an open end of a pipe, includes a rigid body portion including an outer peripheral surface in close proximity to an inner peripheral surface of the pipe when the plug member is in place in the pipe. Sealing means is interposed between the outer peripheral surface of the body portion and the inner peripheral surface of the pipe for preventing debris from entering the pipe. Handle means is connected to the body portion for allowing manual removal of the plug from the pipe.
In one embodiment, the body portion comprises a multi-layer body member to which a peripheral sealing ring is mounted. In another embodiment, a peripheral groove is formed in an outer surface of the body portion, and a resilient sealing ring is positioned in the groove.
In yet another embodiment, the outer edge of the body portion is provided with a ramped or angled surface which contacts an angled sealing surface formed on an internal gasket mounted to the pipe. The angled outer surface of the body portion provides contact with the gasket along less than the entire length of the gasket sealing surface, to facilitate manual removal of the body portion. In one form, the angled outer surface extends linearly, when viewed in cross-section, between the front face and the rear face of the body portion. In another form, a pair of flat surfaces or lands are provided on the outer surface of the body portion. A first, smaller diameter land is located forwardly of the angled surface and a second, larger diameter land is located rearwardly of the angled surface. The angled surface extends between the rear of the smaller diameter land and the front of the larger diameter land.
In a further embodiment, the outer edge of the body portion is defined by a sealing ring which extends throughout the width of the body portion, between the front and rear faces of the body portion. The ring is preferably formed of a thermoplastic material. In one form, the ring defines an annular internal space, with a central lip extending inwardly into the annular space. A laminated core is secured to the ring within the annular internal space defined by the ring. The core consists of a front member and a rear member, placed one on either side of the lip and engaging the edges of the lip. One or more intermediate members may be positioned between the front member and the rear member inwardly of the lip. The front member, the rear member, and any intermediate members are secured together by any satisfactory means, such as threaded fasteners, to secure the members making up the laminated core to the sealing ring. In another form, the temporary plug may be an integral one-piece member molded of a thermoplastic material, with the sealing ring making up the outer peripheral portion of the one-piece member.
The handle means preferably comprises a flexible elongated member, such as a chain or cable, connected to the body portion. The chain or cable normally hangs downwardly to prevent interference with work being performed around the end of the pipe, and it can be grasped by the user to remove the plug member from the pipe.
The invention further contemplates a method of temporarily sealing the end of the pipe, substantially in accordance with the foregoing summary.
Other objects, features and advantages of the invention will be apparent when the description is considered in conjunction with the accompanying drawings.